William leishman



(No Model.)

W. LEISHMAN.

PAPER MAKING MACHINE.

Patented May 19, 1885.

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Il'NrTEfn STATES PATsNTOrrIcr.Qf

WILLIAM LmsHMAN, or Two wATnns MILL, HnMnL-HnMPsTEAD, ooUNTr or nears, ENGLAND.

PAPER-MAKmG MACHINE.

SPECIFICATION forming part of Letters Patent No. 318,378, dated May 19, 1885.

Application filed January I9, 1885. (No model.) Patented in England llIarch 24, 1884, No. 5,360.

To @ZZ whom it may concern:

Be it known that I, VILLIAM LEisHMAN, paper-makers foreman, a subject ofthe Queen of Great Britain and Ireland, and residing at Two Waters Mill, IIemeLHempstead, in the county of Herts, England, have invented certain Improvements in Paper Making Machines, (for which I have made application in Great Britain, No. 5,360, dated March 24.,

lo 1884,) of which the following is a specification.

The object of my invention is to avoid the formation of wire-marks on the back of the paper-web, which result from the pressure of the said web upon the wire-cloth carryingapron, by the upper couch-roll in machines where such parts are employed in the ordinary manner, and, further, to avoid inj uriously stretching the said paper web as it passes from the wire-cloth carrying-apron to the succeed- 2o ing rollers.

In order that the invention maybe fully understood, I will describe the same with reference t0 the accompanying drawing, which is an elevation of so much of a paperanachine as is necessary to illustrate my improvement.

In my improved machine I dispense with the upper couch-roller and employ in lieu thereof an endless felt, a, passing over a system of guide-rollers, b, arranged in any suitable or well-kn0wn manner, a cleaning device of any known construction being placed, as at x, so as to act continuously upon said felt. d is the lower couch-roller, over which is passed the wire-cloth f, said cloth being supported and guided over a system of rollers in the ordinary manner. g is the lirst press-felt, which takes the paper web c as it is delivered from the couch-rolls d and conveys itto the first press-rolls.

None of the parts thus far described form any part of my invention, and may be of the nature herein shown and described or any other.

My invention consists in the employment of a suction or exhaust box located above any one or all of the superposed endless felts or aprons of a paper-machine, whereby the paperpulp web c is drawn or sucked against the surface of said superposed felt or apron. For 5o example, e represents one of my exhaust or suction boxes, which is located over the wirecloth f, just at or near the point where the web c leaves said cloth f, and passes 0n to the first press-roll felt g.

Vith machines as ordinarily constructed the paper-pulp web has nothing to support it in traversing the space between the two endless aprons, and consequently sags down between them, thereby stretehing it to a greater or less extent and causing it to receive the im- 6o print of the wire-cloth as it is deflected over it on the couch-roll d. By the employmentof this suction-box the paper-pulp web is made to adhere to the outer surface of the felt c, and is thereby prevented from sagging. It is also advantageous to employ one of these boxes wherever a felt or apron leaves the paperpulp web, as, for example, where the felt a leaves the web c to be carried on by the first press-felt g, it is well rto place an exhaust-box 7o .behind the felt g, as illustrated at lz.

It is not'deemed necessary to give a minute description of these exhaustboxes, as they are so simple in their nature that a variety 0f forms would readily suggest themselves to one 7 5 skilled in the art. They may lbe simple boxes open at bottom 0r top, and communicating with an air exhaustmechanism of any construction.

I am aware that suction or exhaust boxes 8o suoli as I employ have been employed in paper making machines below the lower aprons over which the paper-pulp is spread for the purpose of extracting the water from said pulp; but such is not the .equivalent ol' S5 my invention.

Having thus described my invention, the following is what I claim as new therein and desire to secure by Letters Patent:

l. In a paper-machine, the combination, 9o with a felt or apron, of an exhaust-box placed above said felt or apron with its opening in proximity thereto, as explained.

2. In a paper-machine, the combination, with a lower couch-roll and the first press-felt, 9 5 of a superposed felt spanning the space between said couch-roll and first press-felt and an exhaust-box placed above said superposed felt, as and for the purpose set forth.

3. The wire-cloth f, the lower couch-roll (l, roo

and therst press-felt g, in Combination with 1o g, and the exhaust-box h, for drawing said paper-pulp web 'from the felt (L onto the felt g, substantially as set forth.

In testimony whereof I h ave signed my name to this speefeation in the presence of two subscribing witnesses.

WILLIAM LEISHMAN.

Vtnesses:

J. NV. WYATT, C. E'. Nash z'lls, IIemeZ-Henwstead.

IV. L. BYNE, l Olm'k t0 Ealwm'd Fweston Buuton, 12 Abczm'oz Lema, Loudon, Notary Public. 

